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Biomedical subjects

F A Shawl

Publications and source records attributed to F A Shawl.

30 records · Page 2Linked to original sources
PubMed1989

Percutaneous cardiopulmonary bypass support in high-risk patients undergoing percutaneous transluminal coronary angioplasty.

Fifty-one consecutive patients in whom percutaneous cardiopulmonary bypass support was instituted to enhance the safety of high-risk elective coronary angioplasty were studied. All patients had a low ejection fraction, a large amount of viable myocardium perfused by the target artery(s) or both. Thirty-five men and 16 women, mean age 63 years, with Canadian Cardiovascular Society class III angina (23 patients) or class IV (28 patients) were studied. There was a history of myocardial infarction in 45 (88%), bypass surgery in 14 (27%) and congestive heart failure in 17 (33%). Forty-six (90%) had impaired left ventricular function. Twenty (39%) had an ejection fraction of less than or equal to 25%. Left main stenosis was present in 9 (18%), 3-vessel disease in 48 (94%) and 2-vessel disease in 2 (4%). Twenty (39%) were considered at a prohibitive risk for bypass surgery (14 were turned down for surgery). Bypass was instituted percutaneously with flows ranging from 2 to 5 liters/min (mean 3.6). Angioplasty was successful in 115 of the 117 lesions attempted with the culprit vessel dilated in all. Dilatation of the only remaining vessel was performed in 14 (27%). Inflation times up to 10 minutes were well tolerated. Bypass was discontinued after a mean bypass time of 37 minutes. Hemostasis was achieved by external clamp compression in 50. There were 3 hospital deaths unrelated to bypass. Patient follow-up at 2 to 8 months (mean 4.9) disclosed 1 late death, 31 (66%) asymptomatic patients, 12 (26%) patients in class I and 4 patients (9%) in class II. Thus, this study demonstrates the safety and efficacy of percutaneous bypass support in selected patients undergoing high-risk coronary angioplasty.

Aged↗
PubMed1989

Emergency percutaneous cardiopulmonary bypass support in cardiogenic shock from acute myocardial infarction.

Emergency percutaneous cardiopulmonary bypass support was instituted in 8 consecutive patients, ages 42 to 80 years, in cardiogenic shock for 30 to 180 minutes (mean 106) due to acute myocardial infarction. The location of the infarction was inferior in 4, anterior in 3 and lateral in 1. Four patients had a history of prior myocardial infarction. Two patients were in cardiac arrest; the remaining 6 had a mean blood pressure of 43 to 55 mm Hg before the bypass. Five had pulmonary capillary Wedge pressure greater than or equal to 20 mm Hg. One patient, with a right ventricular infarction, had a pulmonary wedge pressure of 10 mm Hg. Percutaneous insertion of 20Fr cannulas was carried out. Flow rates of 3.2 to 5.2 liters/min were achieved. Two patients in cardiac arrest regained consciousness while still in ventricular fibrillation or asystole. Left ventricular ejection fraction ranged from 17 to 40% (mean 32). One patient had left main, 4 had multivessel, and 4 had 1-vessel coronary disease. Seven patients had successful angioplasty of 15 of 16 lesions attempted, with all infarct-related vessels successfully dilated. One patient had lesions unsuitable for either bypass or angioplasty and died. Need for blood transfusion was the most frequent complication. One patient required surgical repair of the femoral artery. All 7 patients are alive at a mean follow-up of 8.2 months. It is concluded that cardiopulmonary bypass can be safely instituted percutaneously, hemodynamically stabilize patients in cardiogenic shock and facilitate emergency complex coronary angioplasty, which may be life-saving.

Adult↗
PubMed1989

Asymptomatic left main coronary artery disease and silent myocardial ischemia.

Gathering data on the prognosis, detection, and natural history of asymptomatic left main coronary artery disease with silent myocardial ischemia is difficult. Epidemiologic studies of unexpected death and postmortem studies on silent myocardial infarction suggest this entity to be common. We reviewed 89 consecutive patients with left main coronary artery disease (LMD), defined as 50% or greater reduction of luminal diameter. Of this group, 10 patients (11%) were asymptomatic (ALMD) and 79 patients (88%) were symptomatic (SLMD). All 10 ALMD patients were men, with a mean age of 53 years (range 40 to 65). Treadmill tests (TMT) were performed for: ECG abnormalities six; pre-jogging evaluation two; risk factor evaluation two. The TMT within 9 minutes showed 2 mm or greater ST depression in seven (70%) and 1 to 2 mm in three (30%). Similar TMT results were obtained in the SLMD group, although two patients had negative responses. The degree of stenosis of the left main coronary artery and the frequency of three-vessel disease were similar in both groups. The ejection fraction (EF) and contractile pattern of the left ventricle (LV) were normal in all 10 ALMD patients, but the left ventricular end-diastolic pressure (LVEDP) was abnormal in three (70%). In the SLMD group, 51 (64%) had an abnormal ejection fraction, 50 (65%) had wall motion abnormalities, and 25 (32%) had an abnormal LVEDP.

Adult↗
PubMed1989

Emergent coronary angioplasty in the treatment of acute ischemic mitral regurgitation: long-term results in five cases.

Severe mitral regurgitation in the setting of an evolving myocardial infarction is associated with a high operative mortality rate. Five patients with acute severe mitral regurgitation secondary to ischemic posterior papillary muscle dysfunction underwent emergent percutaneous transluminal coronary angioplasty. Two patients were in cardiogenic shock and required intraaortic balloon counterpulsation. Angioplasty resulted in rapid improvement in hemodynamic variables, and all patients were discharged at a mean of 10 days after the procedure. Long-term follow-up study (mean 35 +/- 6 months) revealed normal mitral valve function angiographically and by Doppler echocardiography in four patients. Repeat angioplasty was required in one patient, and another underwent coronary artery bypass surgery without valve replacement for restenosis. One patient developed progressive mitral regurgitation and required elective mitral valve replacement 12 months after angioplasty. These preliminary findings suggest that emergent coronary angioplasty is a useful therapeutic intervention in the treatment of ischemic mitral regurgitation and is associated with a favorable long-term outcome.

Adult↗
PubMed1989

Percutaneous cardiopulmonary support in high-risk angioplasty.

Percutaneous femoro-femoral cardiopulmonary bypass, cardiopulmonary support (CPS), has a role to play in the management of the high-risk coronary angioplasty patient. This article discusses the basic principles of cardiopulmonary bypass, technique, indications, complications, and future directions of this new addition to interventional cardiology.

Aged↗
PubMed1986

Changes in serum creatine kinase and lactate dehydrogenase caused by acute perioperative myocardial infarction and by transatrial cardiac surgical procedures.

A prospective clinical study was conducted to ascertain if a patient's postoperative elevation in serum creatine kinase MB isoenzyme coupled with determination of the lactate dehydrogenase1/lactate dehydrogenase2 ratio could differentiate whether atrial or ventricular myocardium was the source of these changes. Animal studies have shown that atrial myocardium is as rich a source of creatine kinase MB as is ventricular myocardium. Atrial myocardium has a lactate dehydrogenase1/lactate dehydrogenase2 ratio less than 1.00, whereas in ventricular myocardium the ratio is greater than 1.00. Sixty-four patients were assigned to six groups on the basis of serial electrocardiograms and vectorcardiograms by a cardiologist who was unaware of their clinical courses. The control group (Group 1) consisted of 16 patients admitted to the coronary care unit who had no electrocardiographic changes. Three surgical groups without electrocardiographic or vectorcardiographic evidence of perioperative myocardial infarction were studied: 10 patients undergoing routine coronary artery bypass procedures (Group 2), six adults undergoing repair of secundum atrial septal defect (Group 3), and 13 patients having mitral valve replacement (Group 4). Two groups of surgical patients who had acute perioperative transmural myocardial infarctions confirmed by serial electrocardiograms and vectorcardiograms were studied: 15 patients (Group 5) who had elective coronary artery bypass procedures and four (Group 6) who had mitral valve replacement. This study suggests that serum creatine kinase MB levels in excess of 50 IU/L on the postoperative day 1 and day 2 samples coupled with serum lactate dehydrogenase1/lactate dehydrogenase2 ratios greater than 1.00 on the postoperative day 2 and day 3 samples support the diagnosis of acute myocardial infarction. Patient groups undergoing procedures necessitating atriotomies had average elevations in serum creatine kinase MB and in the lactate dehydrogenase1/lactate dehydrogenase2 ratio, but these were significantly less than those seen when acute perioperative myocardial infarction had occurred.

Adult↗
PubMed1980

Left atrial myxoma: computed tomography as a diagnostic modality.

The workup of left atrial myxomas has variably ranged from a physical examination, laboratory tests, and echocardiography to the invasive modalities of angiography and cardiac surgery. We propose that computed tomography (CT) be considered a sensitive, noninvasive adjuvant in the diagnosis of these tumors. This report describes successful utilization of CT imaging in one such case of proven left atrial myxoma.

Adult↗
PubMedDate not supplied

Probe III catheter, an improved balloon-on-a-wire system: initial experience. Probe III Investigators Group.

Over the last several years, extremely low-profile balloon-on-a-wire catheters have extended the limits of coronary angioplasty. However, the first such fixed-wire catheter, the Probe, experienced a number of mechanical failures, causing the manufacturer to reconfigure the catheter as the Probe III. The current study was therefore undertaken to assess the safety and efficacy of this new device in a variety of cases. The Probe III catheter was used as a primary dilatation device in 157 lesions in 113 patients over a three and one-half month period. One-hundred-six (93%) of the procedures were successful. There were no mechanical failures. The low profile and enhanced trackability of the Probe III catheter led to a high rate of procedural success in a variety of lesions, including extremely tight lesions, distal stenoses, bifurcation lesions, and bend-point lesions. The low profile and enhanced trackability also enabled excellent visualization, as well as quick and successful angioplasty in most patients.

Adult↗